24 Rev. 0. Fisher on Variations of Gravity and their 



2 - )— attraction of the triangular block. 



And a being the distance of the edge of the plateau from 

 Kaliana, 



Attraction of the triangular block 



r J \ 2a sec a / 

 o z/^o 71 " ^ 3A + 2& + A rA , 



But 



S& = 2? 5 



.*. the attraction of the plateau 



a 7 ^3 3A + 2& + £ ~ 7 * Sh + 2k + t 

 = ~ 2 P h 1* 2a +S ^« 2 , - 



To this has to be added the attraction of the slope of the 

 plateau, which we must now calculate. An inspection of the 

 diagram shows that the depth to the bottom of the root 

 (h + k + t) is always less than u, the distance from the station, 

 which justifies the use of the approximate formula. 



Writing t) for h and nrj for t } we have from (A), 



Attraction of the triangular block of height rj 



2a )' 



(2ir V'S 



And it is evident that the attraction of the elementary layer 

 of height $7} with its root will be 



df(v)* o / 2#7r ^3 {3 + n) v + k 



drj 



^"Hl-1 a >' 



The end of the slice Brj, on account of the slope, will be dis- 

 tant from the station, 



b+\{a-b); 



so that, for its attraction at P, we must substitute this quantity 

 for a, and subtract, and the attraction of the slope and its 

 root will be 



u £H -, — rj 



